In recent years, in attaching labels to products in large volume, it has been practiced to form labels in rows and columns on a continuous supporting sheet and to successively attach good labels selectively to products. And, to make sure that labels formed on the continuous supporting sheet are all good, all the labels are individually inspected to separate labels then found defective from labels then ascertained good. It is essential in this case to ensure in separation that defective labels are not mixed in good labels.
In production of labels, techniques of separating defective labels have so far been proposed as in the patent literature cited infra. JP 2011-195151 A discloses a system for a single line of labels which are successively spaced apart from each other by a given distance and adhered to a supporting substrate sheet, the system being provided with a primary line of transport of labels and a line of transport of defective labels. Labels are successively inspected on the primary line of label transport for determination of their quality and a label found defective is peeled off while it is pressed with a pressing member against a pressure receiving member, and is then adhered on a collecting substrate sheet on the line of transport for defective labels.
Also, in JP 2011-148556 A, labels are described which are arranged in a single line on successive elongate label substrates. In continuous transport of the successive elongate label substrates, one label substrate is connected to a next label substrate with a joint label as a particular label to which air is blasted selectively for peeling and removal for label separation.
It is possible, apropos, to substitute labels in a single line on the supporting substrate sheet described in JP 2011-195151 A with those arranged in rows and columns and to substitute the pressing member described therein with an air-blasting mechanism as shown in JP 2011-148556 A for every column such that a blast of air can be applied to a defective label in each row of labels so that the defective label can thereby be forced against the pressure receiving member corresponding to labels in plural columns and adhered onto the collecting substrate sheet on a line of transport for defective labels.
If, however, a plurality of defective labels exist for each row, it has now been found that forcing such defective labels against the pressure receiving member with air of blasts gives rise to a problem that a space between these labels and the pressure receiving member tends to be and to continue to be filled with air of the blasts passing through therearound, finding no way of escape, which prevents separation of defective labels which are to be separated by blasts of air and to be originally separated thereby. Especially, a defective label of three defective labels on adjacent three columns in a row tends to be affected by such a stay of air with the result that the defective label fails to be adhered onto a collecting substrate sheet in a line of transport for defective labels.
Made in view of such problems met in the art, the present invention has for its object to provide a label separating apparatus which ensures that all of a plurality of defective labels possibly extant in any one of the rows can concurrently be transferred without fail discriminatorily onto a different line of transport.